From there, I need some additional information, specifically steps to replicate so I can test the process that you are doing. If you are following the exact steps in the documentation, then please provide these and the slider.zip that you are using.

Beyond that, after you have provided confirmation that you have run through those STS and steps to replicate, I'm happy to take a quick look to see I can import the slider. You will need to provide temporary credentials and confirmation that you have backed up your site, as this reaches beyond the scope of support.